It is known from the prior art to fill containers, in particular under sterile conditions, with a beverage and then to close the containers with container closures. In this case care should also be taken that these container closures cannot contaminate the product itself. For this reason it is known to sterilize the closures before they are attached to the containers. One possibility of sterilization is for the closures to be acted upon with gas such as for example H2O2 vapour or with liquids such as disinfectants. For this type of sterilization, however, complicated conveying, sealing and handling devices are necessary. In addition, in processes of this type use is made of chemicals [which] are expensive, cannot generally be recycled, endanger the health of the user of the plant and have to be removed from the closures again at considerable expense. A further possibility of sterilization is for the container closures to be acted upon with sterilizing radiation, in particular ultraviolet radiation (UV radiation).
A sterilization apparatus is known from U.S. Pat. No. 2,095,502. In this case objects to be cleaned are subjected to a sterilizing light radiation. WO 01/17891 A1 describes an apparatus for filling containers, in which the closures are cleaned before entry into a clean room and in which the cleaning can also be carried out by means of a radiation device which emits UV radiation.
A method and an apparatus for sterilizing containers are known from DE 44 07 183 A1. In this case, containers are moved in a clock-timed manner in a pressure arrangement under a suitably arranged group of screened UV emitters which are permanently switched on. After that, the UV emitters are moved into the bottles, as a result of which an internal sterilization of these containers can be carried out and cleaning is then carried out again.
WO 02/36437 A1 describes methods and apparatus in which packages are subjected to UV radiation. WO 92/18170 discloses a sterilization method in which the material to be sterilized is subjected to UV radiation.
WO 03/021173 A1 describes a radiation apparatus for radiating articles with UV radiation, in which use is made of an elongate UV lamp for emitting UV radiation and an elongate reflector, in order to direct the radiation onto the containers. Apparatus of this type are applied in industrial use in the intended field of the apparatus according to the invention.
DE 202 01 493 U1 describes a radiation apparatus for irradiating an article with UV radiation in the ultraviolet or visible field. In this case one or more light-emitting diodes are used which illuminate the article to be irradiated.
A method and an apparatus for sterilizing containers with UV radiation are known from EP 1 614 630 A1. In this case in particular, the inner face of the container should be treated with UV radiation, in which case UV radiation from a UV source situated outside the container is introduced into the interior of the container.
In this case the apparatus known from the prior art have the problem that the light-generation source is frequently accessible only with difficulty since they take up space inside the plant. Since it is not possible for the UV sources, even in the event of a stoppage of the plant caused by a breakdown, to be switched off, the UV sources are in order to avoid a time-intensive restarting—as is known—provided with screening devices, so-called “shutters”, which during the stoppage prevent the emission of radiation onto the articles to be irradiated. Without these screening devices the articles to be irradiated would be subjected to an excessively intensive radiation, since as a result of the stoppage of the plant they do not move past the radiation source but are stationary. On account of the afore-mentioned screening, a build-up of heat occurs in return inside the radiation source, and as a result a cooling device is necessary. These cooling devices are complicated and, in particular, are not desired in clean or sterile rooms since the hygienic status thereof is difficult to monitor and, in the case of cooling fans for example, undesired air swirling occurs in the sterile room. Although this cooling device is avoided by the apparatus disclosed in the afore-mentioned WO 01/17891 A1, complicated air locks and enclosed conveying devices are made necessary by the radiation before entry into the sterile room.
On account of the complex light-scattering conditions in the interior it is additionally necessary to make conveying channels for the closures satisfactory in order to prevent scattered radiation. As a result, a change of these channels, which is necessary in particular in the case of plants which have to apply all kinds of different container closures to containers, is time-consuming and this leads to an increased loss of production time for the operator of the plant and reduces the productivity of the plant. In addition, it is also not possible to transfer known apparatus for cleaning containers to apparatus for cleaning container closures, since although on the one hand container closures do not require disinfection over large areas, such as for example container walls, on the other hand in the region of the thread they have a very complex structure which is thus difficult to clean. For the reasons described, the cleaning of container closures by means of UV radiation in particular in sterile rooms and in particular in sterile applications has hitherto not been usual, but the predominant practice has been to fall back on the use of disinfectants.